1. Technical Field
The present application relates generally to an improved data processing system and method. More specifically, the present application is directed to a digital thermal sensor test implementation that does not use main core voltage supply.
2. Description of Related Art
The first-generation heterogeneous Cell Broadband Engine™ (Cell BE) processor is a multi-core chip comprised of a 64-bit Power PC® processor core and eight single instruction multiple data (SIMD) synergistic processor cores, capable of massive floating point processing, optimized for compute-intensive workloads and broadband rich media applications. A high-speed memory controller and high-bandwidth bus interface are also integrated on-chip. Cell BE's breakthrough multi-core architecture and ultra high-speed communications capabilities deliver vastly improved, real-time response, in many cases ten times the performance of the latest PC processors. Cell BE is operating system neutral and supports multiple operating systems simultaneously. Applications for this type of processor range from a next generation of game systems with dramatically enhanced realism, to systems that form the hub for digital media and streaming content in the home, to systems used to develop and distribute digital content, and to systems to accelerate visualization and supercomputing applications.
Today's multi-core processors are frequently limited by thermal considerations. Typical solutions include cooling and power management. Cooling may be expensive and/or difficult to package. Power management is generally a coarse action, “throttling” much, if not all, of the processor in reaction to a thermal limit being reached. Other techniques such as thermal management help address these coarse actions by only throttling the units exceeding a given temperature. However, most thermal management techniques impact the real-time guarantees of an application. In order to guarantee the real-time nature of an application in the event of a thermal condition and the accurate throttling that may be required, calibration is usually required. Currently, both analog and core voltage supplies are required during the test and calibration process to power the digital thermal sensor and test logic. However, within the current calibration processes with core voltage supply enabled, the processor consumes a significant amount of power due to leakage current and, in turn, the self-heating due to leakage current elevates the internal processor temperature. This added variable makes the calibration process more difficult and also less accurate.